• Applied Biological Chemistry
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• v.40 no.4
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• pp.334-341
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• 1997

In the laboratory experiment, concentration and rate of runoff of 7 pesticides were measured under the simulated rainfall. Total runoff rate of metolachlor, alachlor, chlorothalonil, chlorpyrifos, EPN, phorate and captafol were 57.0, 14.2, 13.2, 7.9, 7.2, 7.1 and 2.8%, respectively, and the average runoff concentrations were 940, 399, 55, 7.0, 9.3, 151 and 7.0 ppb, respectively. Significant relationship was observed between the runoff rate and water solubility in the laboratory experiment(r=0.923). Even though not very high, relatively significant results were obtained in other experimental conditions. Based on the results, runoff rate prediction$[Y=0.2812{\times}10exp(0.261logWS-0.366)+0.3594{\times}10exp(-0.545logKoc+1.747)+0.3594{\times}10exp(-0.362log\;Kow+1.105]$ and conversion equations were calculated to investigate the possibility of estimating runoff rate in the field by natural rain. Calculated runoff rate by conversion equation was similar to experimental result with captafol in the field while 6 times higher result was obtained by the prediction equation. Therefore, those prediction and conversion equations derived from the laboratory experiment data and physicochemical properties of the pesticides could be used for the prediction of field runoff rate of pesticides by natural rainfall.

• Ocean and Polar Research
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• v.26 no.2
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• pp.199-205
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• 2004

$SiO_2$ and CaO are added to decrease the smelting temperature in the reduction-smelting method for manganese nodule processing. These elements are components of the manganese nodules and might be very important controlling factors in the processing due to the locally variable content. The 707 chemical data of manganese nodules acquired from 1994 to 2001 in KODOS(Korea Deep Ocean Survey) area were used for the hierarchical cluster analysis. The chemical data were classified by the morphological types, and the averages of the chemical data for each station were classified by the facies groups and the localities. All data are plotted on the $SiO_2-CaO-MnO$ phase diagram at $1773^{\circ}K$ to compare with the best compositional area in the nodule smelting. Variations and distributions of $SiO_2$ and CaO in KODOS nodules were also reviewed. The mineral phases assigned by the cluster analysis are CFA(Carbonate Fluorapatite), Fe-oxide, Al-silicate, and Mn-oxide. MnO contents are generally higher than $SiO_2$ contents in most of the morphological types except for the Is- and It-type. The Dt- and Tt-type show wider range and the E-types show high anomaly in their CaO contents. The stations which belong to facies group A and B show generally higher MnO contents than $SiO_2$ contents, however, the stations of facies group C and D show wide range in their MnO and $SiO_2$ contents. It seems to be very important to control the $SiO_2$ contents in the processing because of the wide range in the northern area. The additions of approximately 10 wt.% CaO and 10 wt.% $SiO_2$ are recommended for the northern area, whereas, the additions of approximately 10 wt.% CaO and 20 wt.% $SiO_2$ are recommended for the southern area.

• The Korean Journal of Pharmacology
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• v.30 no.3
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• pp.291-297
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• 1994

Our purpose was to gain insight into a possible modulatory role for ${\mu},\;{\delta},\;and\;{\kappa}$ opioid receptors by neuroleptics (chlorpromazine, thioridazine, haloperidol, sulpiride, and pimozide) in chronic morphine 5 mg/kg and 20 mg/kg treated mouse striatum. We attempted quantitative receptor assays using highly specific radioligands, $[^3H]\;DAGO\;([D-Ala^2,\;N-Mephe^4,\;Glycol^5]\;enkephalin)$, $[^3H]DPDPE\;([D-Pen^2,\;D-Pen^5]\;enkephalin)$ and $[^3H]\;DPN(diprenorphine)$ to measure the binding affinity in the experimental groups. The decrease of $[^3H]DAGO$ binding was potentiated by sulpiride and pimozide in the chronic morphine treatment (5 mg/kg and 20 mg/kg). The decrease of $[^3H]DPDPE$ binding was inhibited by chlorpromazine, thioridazine, haloperidol, sulpiride, and pimozide in chronic morphine treatment (5 mg/kg and 20 mg/kg). The decrease of $[^3H]\;DPN$ binding was significantly inhibited by chlorpromazine, thioridazine, sulpiride, and pimozide in chronic morphine 20 mg/kg treatment. $[^3H]\;DPN$ binding on the neuroleptics was antagonized by naloxone pretreatment in chronic morphine 20 mg/kg treatment. These findings suggest that neuroleptics influence opposing tonically active on the ${\delta},\;and\;{\kappa}$ opioid receptor compared with ${\mu}$ opioid receptor in the chronic morphine treated mouse striatum.

• Korean Chemical Engineering Research
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• v.48 no.1
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• pp.121-127
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• 2010

This study is to optimize the enzyme(lipase) activity for biodiesel production. The ion-exchanged non-woven fabrics(EtA, DEA-EtA non-woven fabric) containing ethanolamine, diethylamine groups are used by radiation induced grafted polymerization onto a non-woven fabric for more effective immobilization of lipase. Since the porous hollow fiber membranes are showed the low throughputibehe non-woven fabric membranes are used for biodiesel production. The physical charateristics of enzyme immobilized and the enzyme activity to EtA and DEA-EtA non-woven fabrics are studied. The EtA non-woven fabrics are quite similar to DEA-EtA non-woven fabric for the amount of enzyme immobilized(EtA non-woven fabric:15.69 mg/g, DEA-EtA non-woven fabric:14.45 mg/g) but DEA-EtA non-woven fabrics have shown the lower permeabiliquite the organic solvent than the EtA non-woven fabrics(EtA non-woven fabric:$3.50mol/h{\cdot}kg$, DEA-EtA non-woven fabric:$0.38mol/h{\cdot}kg$). Optimum characteristics of ehe non-woven fabric membranes and the limilaractivity are also investigated for the effective biodiesel production.

• Journal of Ginseng Research
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• v.24 no.1
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• pp.46-50
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• 2000

This study was carried out to investigate the effect of crude saponin from Korean red ginseng on clinical chemical parameters in ovariectomized rats. The crude red ginseng saponin was prepared by Diaion HP-20 adsorption chromatography and spirit. Tota1 of 50 rats were divided into 5 groups: normal control (NC), sham-ovariectomized (SO), ovariectomized (OR), ovariectomized and saponin treated (OS) and normal control treated with saponin (NS). Saponin was intraperitonally administered for 12 weeks since 1 week before ovariectomy: The body weight of ovariectomized rats showed no significant change but that of NS group showed significant increase when compared with NC group. Platelet counts of serum showed significant increase when treated with saponin regardless of ovariectomy. Triglyceride content of serum in NC group was 152.1 mg/㎗, while that of OR group was decreased to 99.9 mg/㎗ However, when saponin was administered, the content was increased to 138.0 mg/㎗. The weight of spleen also showed significant increase when treated with saponin, while the other organs showed no weight changes. On the other hand, ovariectomy in rats induced decrease in femur weight by 10% when compared with NC group. However, administration of crude saponin in ovariectomized rats recovered the weight of the femur to the similar level of NC (e<0.01 0.05). In addition, femur weight of NS group indicated 10 to 16% higher value than that of NC. These results suggest that Korean red ginseng saponin attenuates phyiological disorders induced by malfunction of ovary.

• Journal of Korea Water Resources Association
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• v.51 no.3
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• pp.263-272
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• 2018

For the design of hydraulic structures, the design flood discharge corresponding to a specific frequency is generally used by using the design storm calculated according to the rainfall-runoff relationship. In the past, empirical equations such as rational equations were used to calculate the peak flow rate. However, as the duration of rainfall is prolonged, the outflow patterns are different from the actual events, so the accuracy of the temporal distribution of the probability rainfall becomes important. In the present work, Huff's quartile method is used for the temporal distribution of rainfall, and the third quartile is generally used. The regression equation for Huff's quadratic curve applies a sixth order polynomial equation because of its high accuracy throughout the duration of rainfall. However, in statistical modeling, the regression equation needs to be concise in accordance with the principle of simplicity, and it is necessary to determine the regression coefficient based on the statistical significance level. Therefore, in this study, the statistical significance test for regression equation for temporal distribution of the Huff's quartile method, which is used as the temporal distribution method of design rainfall, is conducted for 69 rainfall observation stations under the jurisdiction of the Korea Meteorological Administration. It is statistically significant that the regression equation of the Huff's quartile method can be considered only up to the 4th order polynomial equation, as the regression coefficient is significant in most of the 69 rainfall observation stations.

• Journal of the Korean Association of Geographic Information Studies
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• v.11 no.3
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• pp.80-91
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• 2008

The Purpose of this study is the applicaion of social network analysis for expanding the use of spatial data in local government. Spatial data generated from UIS projects play very important roles as a means of supporting decision making and solving complicated urban problems, but the utilization of the spatial data has not reach the expected level, considering to the huge amount of investment. Accordingly, there should be efforts in efficient management of spatial data, establishment of a sharing system, and expanded utilization of spatial data. Social network analysis applied to this research is a theory that explains the behaviors and patterns of units forming the system and measures distances between nodes, strength, etc. based on relations among nodes forming the network and the structural characteristics of the network. According to the results of surveying civil servants who were using spatial data on Busan Metropolitan City, obstacles to the sharing of spatial data were mostly non technical factors related to data users' attitude and their relations with circumstances. In order to expand the use of spatial data, this study performed social network analysis that applied the theory of planned behavior and examined the flow of spatial data, and by doing so, we analyzed related personnel's perception, identified obstacles to data sharing, and suggested a framework for promoting the expanded utilization of spatial data.

• Journal of Korea Port Economic Association
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• v.29 no.2
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• pp.19-38
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• 2013

This paper explores the relationship between shipping firm's investment and debt-ratio characteristics. Using a panel of 41 shipping firms from 2006 to 2011, this study finds evidence that debt/asset ratio and leverage are negatively associated with firm's investment activities. This relationship shows that volume of debt and capital structure are critical decision factor on firm's investment and capital financing. In terms of financial expenses to sales, positive relationship is existed with firm's investment finding that financing cost is important to investment. The previous study of the firm's investment in other sector also shows a negative relationship with debit ratio. This study is also interested in the extent to which the firm's investment is affected by firm size because there is general agreement that smaller firms have less access to external capital markets. As results, smaller companies group have more positive relationship with factors related to financing cost such as financial expenses to sales and tax. On the other hand, bigger companies group shows the evidence that firm investment is positive relationship with asset size. The analysis corresponding to economic fluctuation shows that debit ratio is more sensitive to firm's investment during a recession. On the other hand, financial expenses to sales is more related to firm's investment during an economic boom.

• Journal of Digital Convergence
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• v.15 no.6
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• pp.9-17
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• 2017

The opening of public data has been perceived as a critical factor in deciding a country's rise or fall. Since the global economic crisis, countries around the globe have expanded the supply of public data as a new growth engine to create significant economic effects. As a result, there has been a rising demand for a study on the influence of public data in the private sectors. This study attempted to achieve the following objectives. First, the effects of independent variables-system quality, information quality, information security, social influence, innovation and assistance by the public organization- on the intention to use the public data was examined. Second, the effects of the mediating variables - Perceived Ease of Use (PEU) and Perceived Usefulness (PU) - on the independent variables and intention to use (dependent variable) were investigated. Third, after selecting utilization type, frequency of public data usage and frequency of occupational & e-government service usage as moderating variables, their effects on the relationship between the independent variables and dependent variable (intention to use them in the private sector) were studied. It is expected that the study results would be useful in developing strategies aimed to utilize public data in the private sectors.

• Korean Journal of Environment and Ecology
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• v.33 no.6
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• pp.695-707
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• 2019

This study was intended to suggest the appropriate vegetation management methodology by analyzing phytosociology for ecotourism resources. We carried out the classification and interpretation of the vegetation structure and the analysis of the relationship between communities and environmental conditions in Pocheon valley, Mt. Gaya. The vegetation in Pocheon valley was composed of 5 communities: Pinus densiflora-Quercus mongolica community, Quercus serrata-Quercus variabilis community, Larix kaempferi-Quercus serrata community, Pinus densiflora-Castanea crenata community, and Salix gracilistyla-Phragmites japonica community. The Quercus serrata-Quercus variabilis community was further segmented into two types according to the differences of composition species and location of habitats. The methodologies that satisfy both the use of nature for ecotourism resources and the sustentation of natural vegetation are as follows: - maintenance the present vegetation (dominance species) by strictly avoiding artificial management in the tree layer; - maintenance of the existing vegetation structure through the artificial management of the usual vigorous tree species when the species in the shrub layer grow up to the subtree layer; and - continued artificial management to maintain high balanced diversity and evenness of various species in shrub and herb layers.